1. Field
The present disclosure relates to thermal sensors, more particularly to continuous thermal/overheat sensing in aircraft and vehicles.
2. Description of Related Art
Thermal sensing in aircraft components (e.g., a hot air duct from an engine for cabin environmental control) can utilize heat sensing elements disposed therein for monitoring the components for overheating. Current duct leak overheat detection systems (DLODS) use a nickel-containing inner core electrode and an Inconel 625 outer sheath electrode separated by a granular, porous ceramic or glass layer. This granular, support layer is filled with a salt and acts as an electrical barrier between electrodes when exposed below a threshold temperature. The salt mixture melts at a threshold temperature and causes electrical connection between the inner electrode and the outer electrode such that the salt mixture is a heat-sensing component.
Such conventional methods and systems have generally been considered satisfactory for their intended purpose. However, there is still a need in the art for improved thermal sensors. For aircraft with polymer composite components, the overheat sensing needs to react at lower temperature with faster and accurate response. The present disclosure provides a solution for this need.